Quantifying rock stress and evaluating its significance in the geomechanical design of underground mines.

摘要

Many mining operations in industrialized countries rely on the use of largely mechanized, bulk mining methods, which necessitates the largest possible underground openings. This, combined with a need to mine at increasing depths, makes the potential for catastrophic stress-induced failure a serious operational concern. The empirical approaches to mine design that have historically been used can be insufficient in these circumstances, and therefore there has been a desire to evolve more rational design procedures based increasingly on the principles of engineering mechanics. This has led to the perceived need to accurately measure rock stresses. However, experience has demonstrated that attempts to measure rock stresses can be both expensive and unrewarding. Thus, this work focuses on the development of a procedure that will assist in determining (1) the accuracy with which the rock stresses need to be known, (2) the details of a stress measurement campaign (i.e., methods, locations, number of readings, etc.) designed to achieve the desired level of accuracy, and (3) the geomechanical model that should be used to interpret the results of the campaign. The resulting procedure uses numerical stress analysis to catalyze the information obtained from field investigation, empirical design, and field monitoring techniques, thereby progressively developing an understanding of the nature of rock mass response to mining. As such, the proposed procedure has implications for mine design practices in general, as well as for the implementation of stress measurement campaigns in particular.